#include <stdio.h>
#include <string.h>
char * s_gets(char * st,int n);
#define MAXTITL 40
#define MAXAUTL 40
#define MAXBKS 100 /* 书籍的最大数量*/


struct book{
    char title[MAXTITL];
    char author[MAXAUTL];
    float value;
};
int main() {
    struct book library[MAXBKS];  /*book类型结构的数组*/
    int count = 0;
    int index;

    printf("Please enter the book title. \n");
    printf("Please [enter] at the start of a line to stop.\n");
    while(count < MAXBKS && s_gets(library[count].title,MAXTITL)!= NULL && library[count].title[0]!='\0')
    {
        printf("Now enter the author.\n");
        s_gets(library[count].author,MAXAUTL);
        printf("Now enter the value .\n");
        scanf("%f",&library[count].value);
        while (getchar()!= '\n')
            continue;
        if(count < MAXBKS)
            printf("Enter the next title.\n");
    }

    if(count > 0) {
        printf("Here is the list of your books:\n");
        for (index = 0; index < count; index++)
            printf("%s by %s: $%.2f\n", library[index].title, library[index].author, library[index].value);
    }
        else
            printf("No books? Too bad.\n");


    return 0;
}
char *s_gets(char *st, int n) {
    char *ret_val;
    char *find;

    ret_val = fgets(st, n, stdin);
    if (ret_val) {
        find = strchr(st, '\n'); //查找换行符
        if (find)
            *find = '\0'; // 在此处放置一个空字符
        else
            while (getchar() != '\n')
                continue; //清理输入行中剩余的字符
    }
    return ret_val;
}
